Whether for functionality or aesthetics, some prefer to chill a beverage served “on the rocks” using a relatively large, substantially spherical piece of ice. Devices for forming these ice pieces are described in US Patent Application Publication 2004/0206250, published Oct. 21, 2004, now abandoned, and US Patent Application Publication 2010/0055223, published Mar. 4, 2010. The entire disclosure of these published applications is incorporated herein by reference.
The devices disclosed in these published applications utilize a pair of mold halves formed from a material having relatively high heat conductivity. Those devices use guide rods that are inserted into guide openings to direct the mold halves toward one another in use. This design is rather expensive to manufacture, at least in part because guide bushings are usually required for smooth operation. Additionally, aligning multiple guide rods with guide openings can be cumbersome and the presence of these multiple guide rods around the cavity of at least one mold half can interfere with or limit placement of an ice chunk to be transformed.